Make PageScaleFactor work for oopif subframes.

third_party/WebKit/public/web/WebView.h

 /*
  * Copyright (C) 2009, 2010, 2011, 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 248 matching lines @@
   // Note: this has no effect on plugins.
   virtual float setTextZoomFactor(float) = 0;
 
   // Gets the scale factor of the page, where 1.0 is the normal size, > 1.0
   // is scaled up, < 1.0 is scaled down.
   virtual float pageScaleFactor() const = 0;
 
   // Scales the page without affecting layout by using the visual viewport.
   virtual void setPageScaleFactor(float) = 0;
 
+  // Returns the scale factor clamped within the current limits.
+  virtual float clampPageScaleFactorToLimits(float) const = 0;
+
   // Sets the offset of the visual viewport within the main frame, in
   // partial CSS pixels. The offset will be clamped so the visual viewport
   // stays within the frame's bounds.
   virtual void setVisualViewportOffset(const WebFloatPoint&) = 0;
 
   // Gets the visual viewport's current offset within the page's main frame,
   // in partial CSS pixels.
   virtual WebFloatPoint visualViewportOffset() const = 0;
 
   // Get the visual viewport's size in CSS pixels.
@@ skipping 220 matching lines @@
   // completed.
   WebWidget* widget() { return this; }
 
  protected:
   ~WebView() {}
 };
 
 }  // namespace blink
 
 #endif